The Pontifical Gregorian University’s faculty of philosophy has always maintained the immediate creation of the human
soul by God. The body of man may have evolved, but the soul has not evolved.1 La Vecchia notes that this creation
of the soul is the deciding factor that makes man authentically human.2

The contribution of the parents to the generation of the human child must be considered, since any possible substantial
evolution would arise on the part of the body.

Even before an extensive treatment of opinions, it is appropriate to note the difficulty of the thesis, which philosophers
have debated for over a thousand years before coming to the conclusion that "Man made in the image and likeness of God cannot
have any other origin, at least in his most noble part, if God had not created the soul totally, directly, immediately...This
is the only origin that corresponds to the spiritual nature of the soul as such which is manifest in its highest operations,
especially intellect and will that make man essentially different from brute animals."3 Plato (427-347 B.C.) thought
the soul to pre-exist the body, and with a mixture of poetry and philosophy never resolved the question of the origin of the
soul. We note that if the soul pre-existed (a little or eternally), it would be a necessary being by its very nature, and
Plato did not say why. Neo-Scholastics hold only God is a necessary being. Pre-existence is found in Origin (d. 254), Leibniz
(1646-1716), and Lutoslawski (1863-1954). Tertullian (160- c. 250) held Corporeal Traducianism in his De Anima (c.
208-212), so then the soul could be transferred from parent to child with parental seed; the Stoics thought the soul something
of the air and so corporeal; also the Bible seems to indicate man was brought to life from the corporeal breath of God ("ex
flatu Dei"). St. Augustine did not follow Tertullian, and said the theory was perverse ("quo perversius dici potest").
However, St. Augustine worried that the Creationists did not protect the doctrine of original sin enough ("ut hoc necesse
iam non sit"). In A.D. 515, St. Augustine was very uncertain about Spiritual Traducianism in his Epistle 166 (Migne
Patrologia Latina 33, col. 731-732). St. Gregory the Great (d. 604) in his Letter to Secondino said the question
of the origin of the soul was serious ("gravis"), insoluble, and does not seem to be understood by men (Gregorius Magnus
Epistola 53. 7). St. Isidore of Seville (d. 636) was uncertain about the origin of the soul; "Quod incerta sit animae
origo" (Isidore of Seville De Officiis Ecclesiasticis 2. 23). St. Thomas taught that Corporeal Traducianism was
heretical: "Hereticum est dicere quod anima intellectiva traducatur cum semine" (Aquinas Summa Theologiae 1.
118. 2). In this he followed all of the elements of Aristotle, who said, "So it remains that (of all the forms) only the intellect
comes from the outside, and it alone is of divine origin; in fact there is nothing in common with its action and corporeal
action": "Relinquitur igitur ut intellectus solus ab extrinseco adveniat, isque solus sit divinus. Nihil enim eius actione
communicat corporalis actio" (Aristotle De Generatione Animalium 2. 3. 736 b 27). By using his metaphysics of being,
Aquinas overcame the anthropological views of Plato and Aristotle, of Augustine and Averroes, seeming irreconcilable, and
united them in a superior perspective in which the Empiricism of Aristotle and Averroes was happily married to the Idealism
of Plato and Augustine.4 The positive proof only comes from St. Thomas (Aquinas Summa Theologiae 1. 90.
2) beginning with the fact that the soul is a subsistent form, or a form that possesses its own proper being which is independent
of the body, while the non-subsistent forms, for example the souls of brutes, have a being dependent on the composite of which
it is a part.5